A timing chain will normally last the life of the engine and is replaced during a complete engine rebuild.
Pontiac Grand Prix does not have a timing belt. It has a timing chain and it is replaced when it breaks.
It does not need to be changed unless it fails.
never
If the engine has a timing belt, it should be changed around the 150K mark. If there is a timing chain, it does not have to be changed unless it is damaged.
Timing chains never need to be changed, only belts.
Every 80,000 kms
It has a chain with a cam gear and crank gear.
Should last the life of the engine and is normally changed during an overhaul.
The timing chain is designed to last the life of the engine and is normally only replaced during a complete engine rebuild.
Hopefully, never. I have 3 Jeep Grands with 253K, 203K, and 167K - none has needed a timing chain yet - all V8s.
I think they recommend to change it each 160-180K miles.
check your vehicle specs or do a web search. typically you are looking at 70-100k for most vehicles and if you have an interference engine, you will suffer top end damage if the belt breaks. If it a Grand Caravan it should have the 3.8L engine which has a timing chain which does not require replacement at a regular interval.